The Conceptual Framework of Quantum Field Theory (Paperback)

The book attempts to provide an introduction to quantum field theory emphasizing conceptual issues frequently neglected in more "utilitarian" treatments of the subject. The book is divided into four parts, entitled respectively "Origins", "Dynamics", "Symmetries", and "Scales". The emphasis is conceptual - the aim is to build the theory up systematically from some clearly stated foundational concepts - and therefore to a large extent anti-historical, but two historical Chapters ("Origins") are included to situate quantum field theory in the larger context of modern physical theories. The three remaining sections of the book follow a step by step reconstruction of this framework beginning with just a few basic assumptions: relativistic invariance, the basic principles of quantum mechanics, and the prohibition of physical action at a distance embodied in the clustering principle. The "Dynamics" section of the book lays out the basic structure of quantum field theory arising from the sequential insertion of quantum-mechanical, relativistic and locality constraints. The central role of symmetries in relativistic quantum field theories is explored in the third section of the book, while in the final section, entitled "Scales", we explore in detail the feature of quantum field theories most critical for their enormous phenomenological success - the scale separation property embodied by the renormalization group properties of a theory defined by an effective local Lagrangian.

這本書試圖提供一個量子場論的介紹，強調在更「實用」的處理方式中經常被忽略的概念問題。該書分為四個部分，分別為「起源」、「動力學」、「對稱性」和「尺度」。重點在於概念 - 目標是從一些明確陳述的基礎概念系統地建立理論 - 因此在很大程度上是反歷史的，但也包括了兩個歷史章節（「起源」），以將量子場論置於現代物理理論的更大背景中。該書的其餘三個部分按步驟重建這個框架，從僅有幾個基本假設開始：相對論不變性、量子力學的基本原理以及聚集原則體現的禁止遠距作用。該書的「動力學」部分介紹了從量子力學、相對論和局域性限制的連續插入中產生的量子場論的基本結構。相對論量子場論中對稱性的核心作用在該書的第三部分中進行了探索，而在最後一部分中，名為「尺度」的部分，我們詳細探討了量子場論最關鍵的特徵，即由有效局域拉格朗日量所定義的理論的重整化群性質所體現的尺度分離特性。